sketchframe.java

Beginning Java 2, SDK 1.4 Edition Exercise Code samples for this book

// Frame for the Sketcher application
import javax.swing.*;

import java.awt.Color;
import java.awt.Event;
import java.awt.BorderLayout;
import java.awt.Point;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.Font;
import java.awt.Rectangle;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import java.io.*;

import java.util.Observer;
import java.util.Observable;

import java.awt.print.PrinterJob;
import java.awt.print.PrinterException;
import java.awt.print.Printable;
import java.awt.print.PageFormat;

import javax.print.PrintService;

import javax.print.attribute.PrintRequestAttributeSet;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.standard.Copies;

import java.awt.Graphics;
import java.awt.Graphics2D;

public class SketchFrame extends JFrame
                         implements Constants, ActionListener, Observer, Printable {
  // Print the window
  public int print(Graphics g,
                   PageFormat pageFormat,
                   int pageIndex)
             throws PrinterException {

    if(pageIndex>0)   // Only one page page 0 to be printed
      return NO_SUCH_PAGE;

    // Scale the component to fit
    Graphics2D g2D = (Graphics2D) g;

    // Calculate the scale factor to fit the window to the page
    double scaleX = pageFormat.getImageableWidth()/getWidth();
    double scaleY = pageFormat.getImageableHeight()/getHeight();

    double scale = Math.min(scaleX,scaleY);  // Get minimum scale factor

    // Move paper origin to page printing area corner
    g2D.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
    g2D.scale(scale,scale);                  // Apply the scale factor

    print(g2D);                              // Draw the component
    return PAGE_EXISTS;
  }

  // Method called by SketchModel object when it changes
  public void update(Observable o, Object obj) {
    sketchChanged = true;
  }

  // Constructor
  public SketchFrame(String title, Sketcher theApp) {
    //setTitle(title);                             // Set the window title
    this.theApp = theApp;
    setJMenuBar(menuBar);                       // Add the menu bar to the window
    setDefaultCloseOperation(EXIT_ON_CLOSE);      // Default is exit the application

    JMenu fileMenu = new JMenu("File");          // Create File menu
    JMenu elementMenu = new JMenu("Elements");   // Create Elements menu
    JMenu optionsMenu = new JMenu("Options");              // Create options menu
    JMenu helpMenu = new JMenu("Help");           // Create Help menu

    fileMenu.setMnemonic('F');                   // Create shortcut
    elementMenu.setMnemonic('E');                // Create shortcut
    optionsMenu.setMnemonic('O');                          // Create shortcut
    helpMenu.setMnemonic('H');                    // Create shortcut 

    // Create the action items for the file menu
    newAction = new FileAction("New", KeyStroke.getKeyStroke('N', Event.CTRL_MASK ), "Create new sketch");
    openAction = new FileAction("Open", KeyStroke.getKeyStroke('O', Event.CTRL_MASK), "Open existing sketch");
    saveAction = new FileAction("Save", KeyStroke.getKeyStroke('S', Event.CTRL_MASK), "Save sketch");
    saveAsAction = new FileAction("Save As...", "Save as new file");
    printAction = new FileAction("Print", KeyStroke.getKeyStroke('P',Event.CTRL_MASK), "Print sketch");
    printWindowAction = new FileAction("Print window", KeyStroke.getKeyStroke('W', Event.CTRL_MASK), "Print Current Window");

    addMenuItem(fileMenu, newAction);
    addMenuItem(fileMenu, openAction);
    fileMenu.addSeparator();                                      // Add separator
    addMenuItem(fileMenu, saveAction);
    addMenuItem(fileMenu, saveAsAction);
    fileMenu.addSeparator();                                      // Add separator
    addMenuItem(fileMenu, printAction);
    addMenuItem(fileMenu, printWindowAction);

    // Construct the Element pull down menu
    addMenuItem(elementMenu, lineAction = new TypeAction("Line", LINE, "Draw lines")); 
    addMenuItem(elementMenu, rectangleAction = new TypeAction("Rectangle",RECTANGLE, "Draw rectangles"));
    addMenuItem(elementMenu, circleAction = new TypeAction("Circle", CIRCLE, "Draw circles"));
    addMenuItem(elementMenu, curveAction = new TypeAction("Curve", CURVE, "Draw curves"));
    addMenuItem(elementMenu, textAction = new TypeAction("Text", TEXT, "Draw text"));

    elementMenu.addSeparator();                      // Add separator

    JMenu colorMenu = new JMenu("Color");         // Color sub-menu
    elementMenu.add(colorMenu);                   // Add the sub-menu

    addMenuItem(colorMenu, redAction = new ColorAction("Red", Color.RED, "Draw in red"));
    addMenuItem(colorMenu, yellowAction = new ColorAction("Yellow", Color.YELLOW, "Draw in yellow"));
    addMenuItem(colorMenu, greenAction = new ColorAction("Green", Color.GREEN, "Draw in green"));
    addMenuItem(colorMenu, blueAction = new ColorAction("Blue", Color.BLUE, "Draw in blue"));
    
    menuBar.add(fileMenu);                       // Add the file menu
    menuBar.add(elementMenu);                    // Add the element menu 
    menuBar.add(optionsMenu);                     // Add the options menu
    
    toolBar.setFloatable(false);    // Inhibit toolbar floating
    getContentPane().add(toolBar, BorderLayout.NORTH);

    // Add file buttons
    toolBar.addSeparator();                                 // Space at the start
    addToolBarButton(newAction);
    addToolBarButton(openAction);
    addToolBarButton(saveAction);
    addToolBarButton(printAction);
    
    fileMenu.addSeparator();                                // Add separator
    addMenuItem(fileMenu, closeAction = new FileAction("Exit",
                KeyStroke.getKeyStroke('X',Event.CTRL_MASK ),
                "Exit Sketcher"));

    // Add element type buttons
    toolBar.addSeparator();
    addToolBarButton(lineAction);
    addToolBarButton(rectangleAction);
    addToolBarButton(circleAction);
    addToolBarButton(curveAction);
    addToolBarButton(textAction);

    // Add element color buttons
    toolBar.addSeparator();
    addToolBarButton(redAction);
    addToolBarButton(yellowAction);
    addToolBarButton(greenAction);
    addToolBarButton(blueAction);
    toolBar.addSeparator();                            // Space at the end

    toolBar.setBorder(BorderFactory.createCompoundBorder(       // Toolbar border
                      BorderFactory.createLineBorder(Color.darkGray),
                      BorderFactory.createEmptyBorder(2,2,4,2)));   

    toolBar.setFloatable(false);                       // Inhibit toolbar floating
    getContentPane().add(toolBar, BorderLayout.NORTH); // Add the toolbar
    
    // Disable actions
    //saveAction.setEnabled(false);
    //closeAction.setEnabled(false);
    //printAction.setEnabled(false);

    getContentPane().add(statusBar, BorderLayout.SOUTH);        // Add the statusbar

    // Add the About item to the Help menu
    aboutItem = new JMenuItem("About");           // Create the item
    aboutItem.addActionListener(this);            // Listener is the frame
    helpMenu.add(aboutItem);                      // Add item to menu
    menuBar.add(helpMenu);                        // Add the Help menu

    // Add the font choice item to the options menu
    fontItem = new JMenuItem("Choose font...");
    fontItem.addActionListener(this);
    optionsMenu.add(fontItem);

    fontDlg = new FontDialog(this);
    
    // Create pop-up menu
    popup.add(lineAction);
    popup.add(rectangleAction);
    popup.add(circleAction);
    popup.add(curveAction);
    popup.add(textAction);

    popup.addSeparator();
    popup.add(redAction);
    popup.add(yellowAction);
    popup.add(greenAction);
    popup.add(blueAction);

    customColorItem = popup.add("Custom Color...");    // Add the item
    customColorItem.addActionListener(this);           // and add its listener
    
    frameTitle = title + ": ";
    setTitle(frameTitle + filename);

    if(!DEFAULT_DIRECTORY.exists())
      if(!DEFAULT_DIRECTORY.mkdirs())
        JOptionPane.showMessageDialog(this,
                                      "Error creating default directory",
                                      "Directory Creation Error",
                                      JOptionPane.ERROR_MESSAGE);

    files = new JFileChooser(DEFAULT_DIRECTORY);
  }

  // Method for opening file
  public void openSketch(File inFile) {
    try {
      ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(
                                       new FileInputStream(inFile)));
      theApp.insertModel((SketchModel)in.readObject());
      in.close();
      modelFile = inFile;
      filename = modelFile.getName();            // Update the file name
      setTitle(frameTitle+modelFile.getPath());  // Change the window title
      sketchChanged = false;                     // Status is unchanged
    } catch(Exception e) {
      System.out.println(e);
      JOptionPane.showMessageDialog(SketchFrame.this,
                                    "Error reading a sketch file.",
                                    "File Input Error",
                                    JOptionPane.ERROR_MESSAGE);
    }
  }

  // Prompt for save operation when necessary
  public void checkForSave() {
    if(sketchChanged)
      if(JOptionPane.YES_OPTION ==
            JOptionPane.showConfirmDialog(SketchFrame.this,
                             "Current file has changed. Save current file?",
                             "Confirm Save Current File",
                             JOptionPane.YES_NO_OPTION,
                             JOptionPane.WARNING_MESSAGE))
        saveOperation();
  }

  // Write a sketch to outFile
  private void saveSketch(File outFile) {
    try {
      ObjectOutputStream out =  new ObjectOutputStream(
                                new BufferedOutputStream(
                                new FileOutputStream(outFile)));
      out.writeObject(theApp.getModel());        // Write the sketch to the
                                                 // stream
      out.close();                               // Flush & close it
    } catch(IOException e) {
      System.err.println(e);
      JOptionPane.showMessageDialog(SketchFrame.this,
                                    "Error writing a sketch file.",
                                    "File Output Error",
                                    JOptionPane.ERROR_MESSAGE);
      return;                                    // Serious error - return
    }
    if(outFile != modelFile) {             // If we are saving to a new file
                                           // we must update the window
      modelFile = outFile;                       // Save file reference
      filename = modelFile.getName();            // Update the file name
      setTitle(frameTitle + modelFile.getPath());  // Change the window
                                                   // title
    }
    sketchChanged = false;                       // Set as unchanged
  }

  // Save the sketch if it is necessary
  private void saveOperation() {
    if(!sketchChanged)
      return;

    File file = modelFile;
    if(file == null) {
      file = showDialog("Save Sketch",
                        "Save",
                        "Save the sketch",
                        's',
                        new File(files.getCurrentDirectory(), filename));
      if(file == null || (file.exists() &&                      // Check for existence
        JOptionPane.NO_OPTION ==          // Overwrite warning
            JOptionPane.showConfirmDialog(SketchFrame.this,
                                          file.getName()+" exists. Overwrite?",
                                          "Confirm Save As",
                                          JOptionPane.YES_NO_OPTION,
                                          JOptionPane.WARNING_MESSAGE)))
                                          return;                            // No selected file
    }
    saveSketch(file);    
  }

  // Display a custom file save dialog
  private File showDialog(String dialogTitle,
                          String approveButtonText,
                          String approveButtonTooltip,
                          char approveButtonMnemonic,
                          File file) {                // Current file - if any

    files.setDialogTitle(dialogTitle);
    files.setApproveButtonText(approveButtonText);
    files.setApproveButtonToolTipText(approveButtonTooltip);
    files.setApproveButtonMnemonic(approveButtonMnemonic);
    files.setFileSelectionMode(files.FILES_ONLY);
    files.rescanCurrentDirectory();
    files.setSelectedFile(file);

    ExtensionFilter sketchFilter = new ExtensionFilter(".ske",
                                                    "Sketch files (*.ske)");
    files.addChoosableFileFilter(sketchFilter);            // Add the filter
    files.setFileFilter(sketchFilter);                     // and select it

    int result = files.showDialog(SketchFrame.this, null);  // Show the dialog
    return (result == files.APPROVE_OPTION) ? files.getSelectedFile() : null;
  }

  // Retrieve the pop-up menu
  public JPopupMenu getPopup() {